There are many different types of prior art loudspeakers for use in vehicles. As far as sound reproduction is concerned, one of the more successful members of the prior art is a loudspeaker system which is designed as an elongate arc, which has an upper side connected to the inner roof of the vehicle and has downwardly directed anchorage lugs which are intended for maintaining the loudspeaker arc in the longitudinal beam which, as a rule, are to be found in the region between the roof of the vehicle and its side walls. Such a loudspeaker arc is, generally, equipped with loudspeakers for stereophonic sound reproduction.
The above-described prior art loudspeakers are disclosed in Swedish Patent Specification No. 7603422-2 and are, in practice, produced by the vacuum forming of a plastics material. In order that the loudspeaker arc be capable of withstanding the mechanical forces caused by the loudspeaker units when the loudspeaker system is in use, the plastics material employed must be of some considerable thickness, which entails, in practice, that the anchorage lugs directed downwardly from the loudspeaker arc can only be employed with extreme difficulty (considerable risk for crack formation) in many vehicles in which there are tight radii of curvature in the area of transition between the inner roof of the vehicle and its side walls.
The prior art loudspeaker arcs are of one-piece construction, which entails that, generally speaking, they must be specially adapted to each individual vehicle model. It is easy to understand that this involves considerable problems not only as regards tool costs and storage, but also as regards transport, because of the size of the loudspeaker arcs.